Identification and analysis of the pigment composition and sources in the colored cocoon of the silkworm, Bombyx mori, by HPLC-DAD.

Zhu L, Zhang YQ - J. Insect Sci. (2014)

Bottom Line:
It was found that the mulberry leaf mainly contained four types of pigment: lutein (30.86%), β-carotene (26.3%), chlorophyll a (24.62%), and chlorophyll b (18.21%).The results showed that there were generally two kinds of carotenoids (lutein and β-carotene) in the silk gland and cocoon shell, a little violaxanthin was detected in silk gland, and the pigment found in the blood was mainly lutein in all varieties of silkworm tested.The method used to detect visible pigments reported here could be used to breed new colors of cocoons and to develop and utilize the pigments found in mulberry.

f07_00: Thirty-two kinds of colored-cocoons of Bombyx mori. High quality figures are available online.

Mentions:
Thirty-two yellow-red cocoons are shown in Figure 7. The results (Figure 8) indicate that the color of the cocoon gradually turned from red to yellow to green. The absorption spectrum shows a distinct change. The main absorption peak gradually shifted from 400 nm to 500 nm to 300 nm to 400 nm. As mentioned above, flavonoids are thought to affect the color of the green cocoon series, so the reason for the change may be that the carotenoid content dropped compared to the flavonoids. This would indicate that concentrations of the primary pigments and/or the ratio of different pigments have an important effect on cocoon color.

f07_00: Thirty-two kinds of colored-cocoons of Bombyx mori. High quality figures are available online.

Mentions:
Thirty-two yellow-red cocoons are shown in Figure 7. The results (Figure 8) indicate that the color of the cocoon gradually turned from red to yellow to green. The absorption spectrum shows a distinct change. The main absorption peak gradually shifted from 400 nm to 500 nm to 300 nm to 400 nm. As mentioned above, flavonoids are thought to affect the color of the green cocoon series, so the reason for the change may be that the carotenoid content dropped compared to the flavonoids. This would indicate that concentrations of the primary pigments and/or the ratio of different pigments have an important effect on cocoon color.

Bottom Line:
It was found that the mulberry leaf mainly contained four types of pigment: lutein (30.86%), β-carotene (26.3%), chlorophyll a (24.62%), and chlorophyll b (18.21%).The results showed that there were generally two kinds of carotenoids (lutein and β-carotene) in the silk gland and cocoon shell, a little violaxanthin was detected in silk gland, and the pigment found in the blood was mainly lutein in all varieties of silkworm tested.The method used to detect visible pigments reported here could be used to breed new colors of cocoons and to develop and utilize the pigments found in mulberry.